Toothbrush



Dec. 4 1923.

W. KARL ET AL TOOTHBRUSH Filed Nov. 10 7 Invnfors Patented Dec. 4, 1923.

UNITED STATES ream PATEN .OTFFWE.

WILLIAM KARL AND HEINRICH KARL, F JERSEY CITY, NEW J TOOTHBRUSH.

Application filed November 10, 1917. Serial K020136 14.

To all whom it may concern:

Be it known that we, IVILLIAM KARL, 'a citizen of the United States, andHEINRIOH KARL, a citizen of Germany, residing at 5 Jersey City, countyof Hudson, State of New Jersey, have invented certain new and usefulImprovements in Toothbrushes, of which the following is a specification.

The present invention relates to improve ments in toothbrushes, and hasfor its object to provide means by which the bristles of a tooth-brushmay be protected against breakage at their points of connection to thehandle or backing. At the same time this invention provides means bywhich the bristles would be impregnated, and thereby rendered moreelastic and therefore more resistant to wear.

A further object is to provide a brush which will be moisture-resisting,so that the bristles will not absorb water. In this way the life of thebrush will be materially increased.

With our improvements we further provide a brush which will haveimproved cleansing properties that is, it will polish and clean theteeth in a manner not possible with the ordinary tooth-brush.

IVith this and other objects in view em- 30 bodiments of our inventionare shown in the accompanying drawings, and these embodiments will behereinafter more fully described with reference thereto, and theinvention will be finally pointed out in the claims:

In the accompanying drawings:

Fig. 1 is a side-elevation of a tooth-brush embodying our invention;

Fig. 2 is a horizontal sectional view taken along the line of 2-2 ofFig. 1;

Fig. 3 is a vertical sectional view taken along the line of 33 of Fig.1;

Fig. I is a perspective view showing a device employed in manufacturingthe brush of our invention;

Fig. 5 is a plan view of this device.

Fig. 6 is a perspective view of a tool for use in applying a compoundused in constructing a tooth-brush embodying the invention, a portion ofthe brush being shown in dotted lines; and r Fig. 7 is a side elevationof a brush 'enr bodying a slightly different form of the invention.

imil r re rence charac ers indicate corone, and at the same time to holdthe compound securely with relation to the bristles.

The compound 22 must have certain characteristics: for instance it mustnot be injurious to the teeth or gums. It cannot, therefore, be a veryhard substance but must on the contrary be quite soft. The degree ofsoftness of the compound is preferably such as to cause it to wearslightly when the brush is in use. As one embodiment we propose toemploy para rubber, which is ofa very soft, and at the same time elasticand fiexible, character. Of course other materials which do not containingredients injurious to the teeth may also be employed.

vVe propose to mix rubber with particles of cord or cork-dust .or othermaterial which will not be injurious to .the teeth. In' some cases itmay be preferable to apply two or more layers 35, 36, and 37 all ofdifferent substance, and in such caseswe may provide as the top layer 37para rubber which has a property of constituting polishing meansfor theteeth.

While we have shown an elastic and flexible compound, as extending ashort way along the bristles, it will be understood that it may be onlya thin layer extending slightalmost to the end of the bristles leavingonly the points free.

The bristles may be impregnated with oil 7 or other moisture-resistingsubstances prior to the application of the compound to them, especiallyif the compound which isto be 1y above the base or it may, if desired,reach applied, consists of rubber, but we may pro- 7 vide a compoundorcompounds which are themselves mixed with a suitable oil. In the caselast mentioned, the oil or the compound may be caused to impregnate thebristles in a very thorough manner thus rendering a special impregnationof the bristles unnecessary, A special impregnatlonof the br t es.

I bemoisture-resisting and the bristles will not become water-soaked.

We know that it has heretofore been proposed by others to use certainmaterials such as cement and rubber, the latter beingusually vulcanized,for holding the bristles of a brush firmly in the backing. Inasmuch,however, as the substance thus used were intended to serve only tosecure the bristles to the-backing, theywere so arranged as in realityto form merely a molded portion of the backing, and even when thecompounds composed of rubber were made hard, as by vulcanization, theybecame injurious to the teeth or gums if brought in contact with themwhen using the brush. The compounds employed by us act on the other handnot only to prevent breakage of the bristles, but also to provide apolishing medium for the teeth,.and other purposes for which theconstruction of the prior art are not adapted.

Accordingly the compound or compounds used by us are located ondifferent parts of the bristles from the molded-backing-members proposedby others, and possess characteristics different from those of suchbacking members.

In carrying out our invention it will be understood that any suitablematerial having the properties desired may be employed,

but preferably these should be such that they Y will not have abadtaste, as well as not be injurious to the teeth.

With our improvements it will be seen that the bristles are supported bymeans additional to those usually employed on toothbrushes, andtherefore applied to parts of the bristles which on other tooth-brushesare left free. The grip upon the bristles and the protection affordedthem is therefore such that danger of the bristles breaking off orpulling out is entirely obviated. In the old forms of brushes, thebristles would very soon break off after very little use, the breakingoccurring usually at their base, this being the result of the bristlesbecoming too brittle.

In our invention the bristles may be sufliciently stifi to properlycleanse the teeth, and at the same time they are so flexibly supportedthat they will not break off.

It shoud also be mentioned that the oiling alone will not -suiiic'e torender the bristles continuously elastic and therefore resistant tobreakage, -tastier se the oil will "be gradually The compound 22 may beapplied in various ways, the one herein employed consisting in the useof a tool shown in Figs. 4 and 5, and another tool constructed as shown.in Fig. 6.

In order to apply the compound 22 in a A neat manner, a tool such asshown in Figs. 4 and 5 may be employed. This tool shown in Figs. t and 5consists of a sheet of metal 10 having a slit 11 adapted to embrace thebristles, the side portions of the sheet being bent upwardly andinclined oppositely from each other. The bristles, of the brush areplaced in the slit and held together, whereby the compound 22 will beconfine-d to its proper shape. The tool shown in Fig. 6 comprises asheet 30 of metal sharply bent midway its side edges, as shown at 30 andhaving a slit 30 which extends a portion of its length. I

This tool is used for applying the (10mpound 22 between the rows ofbristles, and between the individual bristles as illustrated in Fig. 6whereby the bristles are divided by the portions of the sheet 30 and thecompound 22 will be poured or placed in the space between the twoupwardlybent in clined portions and 30 of the device. A slight pressurewill force the compound through the slit 30 and cause it to contact withthe base portion of the bristles and with the backing. This method ofapplying the compound prevents smearing of the tips of bristles with thecompound, and by turning the tool horizontally, soiling o-f'the outerportions of the bristles by the compound, will be avoided;

e have illustrated and described a preferred and satisfactory embodimentof our invention, but it is obvious that changes may be made thereinwithin. the spirit and scope thereof as defined in the appended claims,

and that the invention may be embodied 2. In a tooth-brush, a base,bristles set in said base, a latterly disposed cord entwined about saidbristles adjacent said base, and an elastic compound disposed upon saidbase, and imbedding said bristles adjacent their ends set in said baseand gripping said cord, and constituting a flexible strengthening meansadapted to prevent breaking ofl of the bristles set in said base.

3. In a tooth-brush, a base, bristles set in said base, and an elasticcompound having a finely divided polishing substance mixed therein, saidelastic compound disposed upon said base and imbedding the bristles adjacent their endsset in said base, constituting a flexible strengtheningmeans adapted to prevent breaking off of said bristles adj acent saidbase.

4:. In a tooth-brush, a base, bristles set in said base, an elasticadhesive compound disposed upon said base, embedding the bristles for aportion of their length between their base portion and their tip ends,said compound servingto support the bristles yieldingly adjacent theirbase portion to prevent breaking of the bristles, the bristles beingalso impregnated with oil to make them resistant to the absorption ofWater, and to render them less brittle.

5. In a tooth-brush, a backing, a compound disposed upon said backingembedding the bristles between the base and the points thereof forholding the bristles straight and rendering them resistant to breakage,and another compound disposed upon said firstmentioned compound andbeing mixed with cork particles constituting a harmless cleansing andpolishing means for the teeth in co-operation with the bristles.

WILLIAM KARL. HEINRICH KARL.

